Hot-air furnace.



PATENTBD JUNE 27, 1905.

J. 4SMITH. HOT AIR PURNACE. APPLICATION FILED DB0.v 14, 1903.

f lllllmlhY//Illlllll l r l l l l l l l l l I l l a l Patented June 27, 1905.

PATENT OFFICE.

JOSEPH SMITH, OF DENVER, COLORADO.

HOT-AIR FURNACE.

SPECIFICATION forming part of Letters Patent No. 793,617, dated J une 27, 1905. Application filed December 14, 1903. Serial No. 185,145.

To all whom it' may concern,.-

Beit known that I, J osErI-I SMITH, a citizen of the United States of America, residing in the city and county of Denver and State of Oolorado, have invented certain new and useful Improvements in Hot-Air Furnaces; and I do declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, and to the letters of reference marked thereon, which form a part of this specification.

My invention relates to improvements in hot-air furnaces; and it consists of the features, arrangements, and combinations hereinafter described and claimed, all of which will be fully understood by reference to the accompanying drawings, in which is illustrated an embodiment thereof.

In the drawings, Figure 1 is a vertical section taken through a furnace equipped with my improvements. Fig'. 2 is a horizontal section taken on the line 2 2, Fig. 1.

The same reference characters indicate the same parts'in both views.

Let A designate the tire-box, A the grate, and A2 the ash-pit. The cold air is admitted through a flue B into a chamber O, between the outer casing D and the inner wall E, surrounding the combustion-chamber F. The inner surface of the casing E is provided with a number of hot-air iiues Gr, which communicate with the chamber C by openings Gr at their lower ends. These iiues Gr also communicate with the top chamber I-I by means of openings G2 at the tops of the flues. The bottom Gr3 of each of these ues projects inwardly over the fire-box, and the flues therefore project into the combustion-chamber F, but are entirely separated therefrom. The hot-air lines H/Jlead from the top chamber I-I to the various compartments to be heated in the usual manner. A short distance above the openings G the chamber O is provided with a horizontal partition vO', having small orifices O2 allowing a small quantity of cold air to enter the chamber O3 above the partition. This chamber Os communicates with the l'lues Gr by means of openings O1 at the top of the fiues. The openings O2 and O4 give increased draft to the hot air and at the same time allow an outlet for the air in the chamber O3.

In the upper part of the combustion-chamber F is located a box I, having a bottomopening I', adapted to be closed by a damper I2, controlled by a rod I3. Communicating also with this box I and extending outwardly therefrom is a number of tubes J, whose outer extremities are located between the Hues G. The free extremities of these pipes J are open to receive the smoke and products of combustion from the fire-box. These pipes being located between the upper extremities of the flues Gr, the heat and products of combustion are compelled to travel practically the entire distance of the lines Gr on the outside before escaping into the smoke-pipe K, which leads from the box I.

In the use of the furnace the damper I should be left open or thrown to the position shown by dotted lines in Fig. l when the fire is first started. This allows the smoke to escape directly from the combustion-chamber to the smoke-iiue K, as well as by way of the auxiliary smoke lues or branch pipes J. When, however, the fire is well started, the damper I may be closed or thrown to the position shown by full lines in Fig. l, after which the smoke or products of combustion can only escape from the combustion-chamber by way of the pipes J, compelling them to travel outwardly between the upper extremities of the hot-air fines, thus thoroughly heating said flues and the air passing through them to the compartments to be warmed.

Attention is called to the fact that the inner wall or casing E, together with the fines Gr, may be formed or molded as an integral casting. The horizontal partition C may besecured to the said casting by means of screws or bolts, as shown in Fig. l of the drawings, the same being passed through a depending flange formed on the partition.

Having thus described my invention, what I claim is l. Ahot-air furnace having a casing, a combustion-chamber, a cold-air duct and a smokepipe, the casing surrounding the combustion- IOC) chamber, and provided with iiues which extend inwardly over the fire-box and upwardly through the combustion -ehamber, the said lues communicating with the cold-air duet at the bottom and being provided above with an opening for the escape of the hot air, the said iiues being cut off from communication with the combustion-chamber, and fines mounted in the upper part of the combustion-chamber and having one extremity in connection with the smoke-pipe, the said iiues extending outwardly between the hot-air flues toward the outer wall of the combustion-chamber with which the outer extremities of the iues communicate.

2. In a hot-air furnace provided with a combustion chamber having an outlet for the smoke, the combination with the outer shell of the furnace, of an inner wall or casing surrounding the combustion-chamber the outer shell and inner wall being separated by,a suitable space, the inner wall being provided with ues communicating at the bottom with the space between the inner and outer easings and having an outlet at the top for the hot air, the inner wall or casing closing said fines on one side, and the said iiues projecting inwardly over the fire-box and extending upwardly through the combustion-chamber, and a number of iiues suitably mountedfin the upper part of the combustion-chamber adjacent the outlet for the smoke or products of combustion and communicating with the said outlet at one extremity, the said iiues projecting outwardly toward the outer wall of the combustion-chamber and communicating therewith at their outer extremities.

3. In a hot-air furnace,the combination with inner and outer separated casings forming a chamber, and a cold-air duct communicating with the chamber between said casings, of hotair iiues connected with the inner casing and projecting inwardly into the combustionchamber and upwardly through said chamber, the inner easing being provided with openings at the bottom leading from the space between the two casings into cach hot-air flue, and the latter having a hot-air-cscape opening at the top, and a horizontal partition located in the chamber between the two casings and above the openings leading 'from the said chamber to the hot-air flues, the said partition being provided with small oriiices, the upper portion of each hot-air iue being provided with an opening leading from the chamber between the two casings.

4. In a hot-air furnace having a {ire-box, a combustion-chamber, a cold-air duct and a smoke-pipe, the combination of an inner wall surrounding the fire-box and vertically-disposed hot-air lues extending inwardly from said wall and cast integral therewith whereby the said inner wall closes the said fines on one side, the flues having bottom openings communicating with the cold-air duct and hot-airescape upper openings, and iiues suitably mounted in the upper part of the combustionchamber and communicating with `the smokepipe at one extremity and with the combustion-chamber at the opposite extremity.

5. 'In a hot-air fu rnace provided with a combustion-chamber and smoke-pipe, the combination of an inner wall surrounding the combustion-chamber and having vertically-disposed hot-air iiues connected therewith and located in the combustion-chamber, the said fines being provided with cold-.air openings at their lower portions and hot-air-escape openings in their upper portions, and branch pipes or auxiliary iues communicating with the smoke-pipe and located in the upper part of the combustion-chamber, the said auxiliary iiues projecting outwardly between the hotair flues and having their free extremities open for the entrance of the smoke and products of combustion.

6. In a hot-air furnace, the combination with a smoke-stack of a combustion-chamber provided with vertically-disposed hot-air fines, of a box or receptacle mounted in the upper part of the combustion-chamber and communicating with the smoke-stack, the said box or receptacle being provided with auxiliary openended smoke pipes or lues communicating with the said box or receptacle at one extremity, while their outer extremities are located between the hot-air flues in the upper part of the combustion-chamber.

7 In a hot-air furnace, the combination with a smoke-stack and a combustion-chamber provided with vertically-disposed hot-air lues, of a box or receptacle mounted in the upper part of the combustion-chamber and communicating with the smoke-stack, the said box or receptacle being provided with auxiliary openended smoke pipes or fines communicating with the said box or receptacle at one extremity, the fines extending outwardly from the box toward the outer wall of the combustion-chamber their outer extremities communicating with the combustion-chamber, and a damper connected with the said box whereby direct communication may be made with the combustion-chamber.

8. In a hot-air furnace, the combination with a smoke-stack and a combustion-chamber, of a box or receptacle mounted in the upper part of the said chamber and communicating with the smoke-stack, the said box being provided with' auxiliary open-ended smoke pipes or fines communicating with the said box at one extremity the fines extending outwardly from the box toward the outer wall of the combustion-chamber their outer extremities communicating with the combustion-chamber.

9. In ahot-air furnace,the combination with a smoke-stack and a combustion-chamber provided with vertieally-disposed hot-air iiues, of a box or receptacle mounted in the upper part ot' the combustion-chamber and communicat- IDO ing with the smoke-stack, the said box or receptacle being provided with auxiliary openended smoke pipes o1' iiues communicating with the said box or' receptacle at one ex- 5 tremity, the ues extending outwardly from the box toward the outer wall of the eornbus# tion-chamber their outer extremities communicating' with the combustion chamber, a damper connected with the said box whereby IO direct Communication may be made with the combustion-chamber, and suitable meansfor Controlling the damper' from the outside of the furnace.

In testimony whereof I affix my signature in presence of Vtwo witnesses. I5

JOSEPH SMITH.

Witnesses:

DENA NELsoN, A. J. OBRIEN. 

